Methods for forming a rhenium-containing film on a substrate by a cyclical deposition process and related semiconductor device structures

ABSTRACT

Methods for forming a rhenium-containing film on a substrate by a cyclical deposition are disclosed. The method may include: contacting the substrate with a first vapor phase reactant comprising a rhenium precursor; and contacting the substrate with a second vapor phase reactant. Semiconductor device structures including a rhenium-containing film formed by the methods of the disclosure are also disclosed.

FIELD OF INVENTION

The present disclosure relates generally to methods for forming arhenium-containing film on a substrate by a cyclical deposition processand particularly methods for forming a rhenium-containing film by acyclical deposition process utilizing a rhenium precursor.

BACKGROUND OF THE DISCLOSURE

Rhenium-containing films may be utilized in a wide variety of technologyapplications. For example, elemental rhenium films may be used as acatalyst, in high-temperature superalloys, in superconductingapplications, in adhesion layers, in liners, in diffusion barriers, inseed layers to improve growth of other materials, and in microelectronicapplications. In addition, rhenium oxides may exhibit a low electricalresistivity and therefore may be utilized as electrodes to semiconductordevice structures, such as, for example, a dynamic random-access memory(DRAM) device. Furthermore, rhenium sulfides, such as, for example,rhenium disulfide (ReS₂), have been shown to behave in a manner similar2D materials, even in 3D bulk form. Therefore, rhenium sulfides may findapplications in tribology, other low-frication applications, solar cellapplications, quantum computing, and ultrafast data processing.Accordingly, methods for forming rhenium-containing films and relatedsemiconductor device structures including rhenium-containing films arehighly desirable.

SUMMARY OF THE DISCLOSURE

This summary is provided to introduce a selection of concepts in asimplified form. These concepts are described in further detail in thedetailed description of example embodiments of the disclosure below.This summary is not intended to identify key features or essentialfeatures of the claimed subject matter, nor is it intended to be used tolimit the scope of the claimed subject matter.

In some embodiments, methods for forming a rhenium-containing film on asubstrate by a cyclical deposition process are provided. The methods maycomprise: contacting the substrate with a first vapor phase reactantcomprising a rhenium precursor selected from the group comprising: arhenium oxyhalide precursor, an alkyl rhenium oxide precursor, acyclopentadienyl based rhenium precursor, or a rhenium carbonyl halideprecursor; and contacting the substrate with a second vapor phasereactant.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the attachedfigures, the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

While the specification concludes with claims particularly pointing outand distinctly claiming what are regarded as embodiments of theinvention, the advantages of embodiments of the disclosure may be morereadily ascertained from the description of certain examples of theembodiments of the disclosure when read in conjunction with theaccompanying drawings, in which:

FIG. 1 illustrates a non-limiting exemplary process flow, demonstratinga method for forming a rhenium oxide film on a substrate by a cyclicaldeposition process according to the embodiments of the disclosure;

FIG. 2 illustrates a non-limiting exemplary process flow, demonstratingan additional method for forming a rhenium oxide film on a substrate bya cyclical deposition process according to the embodiments of thedisclosure;

FIG. 3 illustrates a non-limiting exemplary process flow, demonstratinga further method for forming a rhenium oxide film on a substrate by acyclical deposition process according to the embodiments of thedisclosure;

FIGS. 4A-4C illustrate cross-sectional schematic diagrams ofsemiconductor structures that may be formed by a process for forming alow resistivity rhenium oxide film on a substrate by a cyclicaldeposition process according to the embodiments of the disclosure;

FIG. 5 illustrates a non-limiting exemplary process flow, demonstratinga method for forming a rhenium sulfide film on a substrate by a cyclicaldeposition process according to the embodiments of the disclosure;

FIG. 6 illustrates a non-limiting exemplary process flow, demonstratingan additional method for forming a rhenium sulfide film on a substrateby a cyclical deposition process according to the embodiments of thedisclosure;

FIG. 7 illustrates a non-limiting exemplary process flow, demonstratinga method for forming an elemental rhenium film on a substrate by acyclical deposition process according to the embodiments of thedisclosure;

FIG. 8 illustrates a non-limiting exemplary process flow, demonstratingan additional method for forming an elemental rhenium film on asubstrate by a cyclical deposition process according to the embodimentsof the disclosure;

FIG. 9 illustrates a cross-sectional schematic diagram of asemiconductor device structure including a rhenium-containing filmformed according to the embodiments of the disclosure; and

FIG. 10 illustrates an exemplary reaction system configured forperforming the cyclical deposition methods according to the embodimentsof the disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below.

The illustrations presented herein are not meant to be actual views ofany particular material, structure, or device, but are merely idealizedrepresentations that are used to describe embodiments of the disclosure.

As used herein, the term “rhenium oxyhalide precursor” may refer to amolecule having the general formula Re_(a)O_(b)X_(c) wherein Re isrhenium, p is oxygen, X is a halogen atom, such as, for example,fluorine (F), chlorine (Cl), bromine (Br), or iodine (I), and a, b, andc, are integers equal to 1 or greater.

As used herein, the term “cyclical chemical vapor deposition” may referto any process wherein a substrate is sequentially exposed to two ormore volatile precursors, which react and/or decompose on a substrate toproduce a desired deposition.

As used herein, the term “substrate” may refer to any underlyingmaterial or materials that may be used, or upon which, a device, acircuit, or a film may be formed.

As used herein, the term “atomic layer deposition” (ALD) may refer to avapor deposition process in which deposition cycles, including aplurality of consecutive deposition cycles, are conducted in a reactionchamber. Typically, during each cycle the precursor is chemisorbed to adeposition surface (e.g., a substrate surface or a previously depositedunderlying surface such as material from a previous ALD cycle), forminga monolayer or sub-monolayer that does not readily react with additionalprecursor (i.e., a self-limiting reaction). Thereafter, if necessary, areactant (e.g., another precursor or reaction gas) may subsequently beintroduced into the process chamber for use in converting thechemisorbed precursor to the desired material on the deposition surface.Typically, this reactant is capable of further reaction with theprecursor. Further, purging steps may also be utilized during each cycleto remove excess precursor from the process chamber and/or remove excessreactant and/or reaction byproducts from the process chamber afterconversion of the chemisorbed precursor. Further, the term “atomic layerdeposition,” as used herein, is also meant to include processesdesignated by related terms such as, “chemical vapor atomic layerdeposition”, “atomic layer epitaxy” (ALE), molecular beam epitaxy (MBE),gas source MBE, or organometallic MBE, and chemical beam epitaxy whenperformed with alternating pulses of precursor composition(s), reactivegas, and purge (e.g., inert carrier) gas.

As used herein, the term “film” and “thin film” may refer to anycontinuous or non-continuous structures and material formed by themethods disclosed herein. For example, “film” and “thin film” couldinclude 2D materials, nanorods, nanolaminates, nanotubes, ornanoparticles or even partial or full molecular layers or partial orfull atomic layers or clusters of atoms and/or molecules. “Film” and“thin film” may comprise material or a layer with pinholes, but still beat least partially continuous.

A number of example materials are given throughout the embodiments ofthe current disclosure, it should be noted that the chemical formulasgiven for each of the example materials should not be construed aslimiting and that the non-limiting example materials given should not belimited by a given example stoichiometry.

The present disclosure includes methods and related semiconductor devicestructures that may be used to form and may utilize rhenium-containingfilms. Such rhenium containing films, such as, for example, elementalrhenium films, rhenium oxide films, rhenium sulfide films, and rheniumboride films, may be utilized in a wide variety of technologyapplications.

As a non-limiting example, certain rhenium oxide films, such as, forexample, rhenium trioxide (ReO₃), may exhibit very low electricalresistivity and may therefore be exploited in a number of semiconductordevice applications, including, but not limited to, deviceinterconnects, barrier layers, Schottky devices,metal-insulator-semiconductor (MIS) devices, metal-insulator-metaldevices (MIM), and as a portion of a gate electrode.

Rhenium oxides may be also utilized in the doping of semiconductordevices. For example, rhenium oxides may be utilized to modulate theconductivity of semiconductor materials as well as to adjust theadhesion of certain materials. In additional examples, rhenium oxidesmay be utilized to form interesting mixed compounds, such as, in case ofsolid-solid reactions, for example.

Due to the attractive physical properties of rhenium oxides, such as,for example, rhenium dioxide, rhenium trioxide, or di-rheniumhepta-oxide, several new applications can be exploited. In someembodiments, rhenium oxides may be utilized for bottom up filling orfilling of trench structures, pits, or gap structures, in complex 3Dstructures. The bottom-up and/or gap filling by a rhenium oxide can berealized in many ways, such as, but not limited to, depositing rheniumoxide at low deposition temperatures and subsequently annealing thedeposited rhenium oxide film at a higher temperature to reflow therhenium oxide film into the lower regions of a 3D structure. Theannealing temperature of the rhenium oxide film may be greater than 50°C., or greater than 100° C., or greater than 20° C., or greater than300° C., or even greater than 350° C. The annealing of the rhenium oxidefilm may be carried out in an oxidative or a reductive environment inorder to maintain a specific composition of the rhenium oxide film. Forexample, annealing of the rhenium oxide film may be performed in anenvironment comprising at least one of nitrogen monoxide (NO), nitrogendioxide (NO₂), a sulfur pxxide (e.g., SO₂ or SO₃), oxygen, or water.

As a further non-limiting example, a rhenium oxide, such as, Re₂O₇ maybe utilized as a source material for a chemical vapor deposition (CVD)process, wherein Re₂O₇ may begin to sublime above a temperature ofapproximately 100° C., or above a temperature of approximately 150° C.,or even above a temperature of approximately 180° C., in order todeposit Re₂O₇ for thin film applications and/or gap fill applications.

In some embodiments of the disclosure, the deposition temperature may becarefully controlled such that a first composition of a rhenium oxidefilm may be deposited over a second composition of a rhenium oxide film,wherein the first composition and the second composition are differentfrom one another. For example, at a deposition temperature betweenapproximately 22° C. and 350° C. a rhenium oxide film not comprising thecomposition Re₂O₇ may be deposited.

In some embodiments, the rhenium oxide films may be deposited over atemplate structure, such as, for example, corrugated surfaces, and/orpatterned surfaces, for the formation of quantum dots, nanodots,nanowires, or nano-patterns, comprising a rhenium oxide material. Insuch embodiments, the initial material or the final material may beeither one of a rhenium oxide, an elemental rhenium metal, a rheniumboride, or a rhenium sulfide. Depending upon the desiredrhenium-containing material, various processing steps, such as, forexample, oxidation, reduction, or sulfidization, of the initialrhenium-containing film may be utilized. An annealing step, as describedabove, may also be utilized to enable the rhenium-containing material toaccumulate at the lower vertices of the corrugations or lower regions ofa 3D structure.

In some embodiments, the deposited rhenium-containing films, or theiralloys, may contain either boron, sulfur, carbon, nitrogen, phosphorus,or a combination thereof. In some embodiments, rhenium-containing filmsare categorized as one of the possible phases of rhenium carbides,rhenium borides, rhenium nitrides, rhenium phosphides, or in some casesmay contain more than two elements. For example, rhenium-containingfilms may comprise boron and carbon, nitrogen and boron, or a possiblecombination of either boron, carbon, nitrogen, and phosphorus. In someembodiments of the disclosure, the rhenium-containing film may comprisea rhenium boron carbide (ReBC), a rhenium diboride (ReB₂), adirheniumtriboride (Re₂B₃), or a rhenium boride (ReB, Re₃B₇, Re₃B andRe₂B).

In some embodiments of the disclosure, the rheZnium-containing films maycomprise boron, carbon, nitrogen, sulfur, phosphorus, or any possiblecombination thereof. The non-limiting applications of such mixed alloysof rhenium, boron, carbon, nitrogen, or phosphorus, may be utilized asadhesion improving layers, seed layers, diffusion barriers, hardcoatings, high bulk modulus super hard layers, or liners.

In some embodiments, the rhenium-containing film may comprise at leastone of ReBC, ReB, ReC, Re₃P₄, Re₂P, ReP₄, Re₃N, Re₂N, ReN, ReN₂, ReN₄,Re₂C, ReC, Re₄C, ReB₂. In some embodiments, the rhenium-containing filmsmay be used as: superconducting layers, hard masks in patterningapplications, etch stop layers in patterning applications, coatings forthe reaction chamber as well as its components in either deposition aswell as etch reactors, protective coatings against etching chemistries,and ReP₄ as semiconducting layers.

In some cases, it is desirable to form air-gaps and low boiling pointrhenium oxide films may be exploited in such applications. For example,annealing a rhenium oxide film above a temperature of approximately 400°C. may sublime a rhenium oxide film completely from a filled gap featureor sublime a deposited rhenium oxide film. In some embodiments, thesublimation of the rhenium oxide film may leave behind a void oralternatively the rhenium oxide film may be utilized as a sacrificiallayer and/or as a patterning layer in patterning applications.

In some embodiments, a rhenium-containing film may be utilized inback-end-of-line (BEOL) applications, such as a metal contact, whereinthe metal contact may be deposited on top of an underlying liner layer,adhesion layer, seed layer, or diffusion barrier layer, and in someapplications the metal contact may be capped by a metal alloy. Forexample, in some applications the metal interconnect may be elementalrhenium and may be deposited on top of an underlying rhenium alloy, suchas, for example, a rhenium carbide, a rhenium boride, a rhenium nitride,or a rhenium phosphide. In some embodiments, the metal precursorutilized to deposit the metal contact is same as that utilized in thedeposition of a liner layer, an adhesion layer, a seed layer, or adiffusion barrier layer, and only the choice of the second reactantand/or process conditions (e.g., deposition temperature) may bedifferent. This approach may be advantageous in processing as only onemetal precursor is used and this approach can be applied to otherprocesses that utilize different materials, such as, for example, cobaltas the metal contact or interconnect, and cobalt phosphide as anadhesion layer, or a liner layer. Similar approaches can be utilized forruthenium-based processes and its related carbides.

In addition, certain rhenium oxide films, such as, for example, rhenium(VII) oxide (Re₂O₇), may exhibit dielectric properties and therefore maybe utilized in DRAM devices, and as capacitor structures. ReO₂ may findapplications in spintronic devices as well as memory devices, such as,Resistive RAM, for example. In some embodiments, the rhenium oxides maybe utilized in catalysis sciences. In some embodiments, the depositedrhenium-containing films may promote selective deposition or etching.For example, the catalytic effect of ReO_(x) may assist several ALDprecursors to react or decompose on its surface.

Furthermore, certain rhenium oxide films, such as, for example, rheniumtrioxide (ReO₃) may exhibit a low melting point and the low metalingpoint may be taken advantage of by capping the rhenium oxide film with acapping layer, such as, for example, titanium nitride (TiN), andsubsequently thermally annealing the rhenium oxide film to either form asingle crystal rhenium oxide film or increase the crystal grain sizes ofthe crystallites comprising the rhenium oxide film thereby decreasingthe electrical resistivity of the rhenium oxide film.

Therefore, the embodiments of the disclosure may comprise methods forforming a rhenium-containing film on a substrate by a cyclicaldeposition process. In some embodiments, the method may comprise:contacting the substrate with a first vapor phase reactant comprising arhenium precursor selected from the group comprising: a rheniumoxyhalide precursor, an alkyl rhenium oxide precursor, acyclopentadienyl based rhenium precursor, or a rhenium carbonyl halideprecursor; and contacting the substrate with a second vapor phasereactant.

The methods of formation of rhenium-containing films disclosed hereinmay comprise a cyclical deposition process, such as, for example, atomiclayer deposition (ALD), or cyclical chemical vapor deposition (CCVD).

A non-limiting example embodiment of a cyclical deposition process mayinclude atomic layer deposition (ALD), wherein ALD is based on typicallyself-limiting reactions, whereby sequential and alternating pulses ofreactants are used to deposit about one atomic (or molecular) monolayerof material per deposition cycle. The deposition conditions andprecursors are typically selected to provide self-saturating reactions,such that an absorbed layer of one reactant leaves a surface terminationthat is non-reactive with the gas phase reactants of the same reactants.The substrate is subsequently contacted with a different reactant thatreacts with the previous termination to enable continued deposition.Thus, each cycle of alternated pulses typically leaves no more thanabout one monolayer of the desired material. However, as mentionedabove, the skilled artisan will recognize that in one or more ALD cyclesmore than one monolayer of material may be deposited, for example, ifsome gas phase reactions occur despite the alternating nature of theprocess.

In an ALD-type process utilized for the formation of arhenium-containing film, such as, for example, an elemental rheniumfilm, a rhenium oxide film, a rhenium sulfide film, or a rhenium boridefilm, one deposition cycle may comprise exposing the substrate to afirst vapor phase reactant, removing any unreacted first reactant andreaction byproducts from the reaction chamber, and exposing thesubstrate to a second vapor phase reactant, followed by a second removalstep. In some embodiments of the disclosure, the first vapor phasereactant may comprise a rhenium precursor and the second vapor phasereactant may comprise at least one of an oxygen containing precursor, asulfur containing precursor, a boron containing precursor, or a hydrogencontaining precursor.

In some embodiments of the disclosure, a boron containing precursor maycomprise boranes of general formula B_(n)H_(n+x) where n and x areintegers greater than or equal to 1. In some embodiments, a boroncontaining precursor may comprise alkyl borates of general formulaR¹R²R³O₃B, where R is any alkyl or aryl group. In some embodiments, aboron containing precursor may comprise at least one of boron hydride(BH₃), diborane (B₂H₆), decaborane (B₁₀H₁₄), tetraborane (B₄H₁₀),trimethylborate, or triethylborate.

Precursors may be separated by inert gases, such as argon (Ar) ornitrogen (N₂), to prevent gas-phase reactions between reactants andenable self-saturating surface reactions. In some embodiments, however,the substrate may be moved to separately contact a first vapor phasereactant and a second vapor phase reactant. Because the reactionsself-saturate, strict temperature control of the substrates and precisedosage control of the precursors may not be required. However, thesubstrate temperature is such that an incident gas species does notcondense into monolayers nor decompose on the surface. Surplus chemicalsand reaction byproducts, if any, are removed from the substrate surface,such as by purging the reaction space or by moving the substrate, beforethe substrate is contacted with the next reactive chemical. Undesiredgaseous molecules can be effectively expelled from a reaction space withthe help of an inert purging gas. A vacuum pump may be used to assist inthe purging.

Reactors capable of being used to deposit rhenium-containing films canbe used for the cyclical deposition processes described herein. Suchreactors include ALD reactors, as well as CVD reactors, configured toprovide the precursors. According to some embodiments, a showerheadreactor may be used. According to some embodiments, cross-flow, batch,minibatch, or spatial ALD reactors may be used.

In some embodiments of the disclosure, a batch reactor may be used. Insome embodiments, a vertical batch reactor may be used. In otherembodiments, a batch reactor comprises a minibatch reactor configured toaccommodate 10 or fewer wafers, 8 or fewer wafers, 6 or fewer wafers, 4or fewer wafers, or 2 or fewer wafers. In some embodiments in which abatch reactor is used, wafer-to-wafer non-uniformity is less than 5% (1sigma), or less than 3%, or less than 2%, or less than 1%, or even lessthan 0.5%.

The exemplary cyclical deposition processes described herein mayoptionally be carried out in a reactor or reaction chamber connected toa cluster tool. In a cluster tool, because each reaction chamber isdedicated to one type of process, the temperature of the reactionchamber in each module can be kept constant, which improves thethroughput compared to a reactor in which the substrate is heated up tothe process temperature before each run. Additionally, in a cluster toolit is possible to reduce the time to pump the reaction chamber to thedesired process pressure levels between substrates. In some embodimentsof the disclosure, the exemplary cyclical deposition processes for theformation of rhenium-containing films disclosed herein may be performedin a cluster tool comprising multiple reaction chambers, wherein eachindividual reaction chamber may be utilized to expose the substrate toan individual precursor gas and the substrate may be transferred betweendifferent reaction chambers for exposure to multiple precursors gases,the transfer of the substrate being performed under a controlled ambientto prevent oxidation/contamination of the substrate. In some embodimentsof the disclosure, the cyclical deposition processes for the formationof rhenium-containing films may be performed in a cluster toolcomprising multiple reaction chambers, wherein each individual reactionchamber may be configured to heat the substrate to a differenttemperature.

A stand-alone reactor may be equipped with a load-lock. In that case, itis not necessary to cool down the reaction chamber between each run.

In some embodiments, a deposition process utilized in the formation of arhenium-containing film may comprise a plurality of deposition cycles,for example ALD cycles or cyclical CVD cycles.

In some embodiments the cyclical deposition process may be a hybridALD/CVD or a cyclical CVD process. For example, in some embodiments, thegrowth rate of the ALD process may be low compared with a CVD process.One approach to increase the growth rate may be that of operating at ahigher substrate temperature than that typically employed in an ALDprocess, resulting in some portion of a chemical vapor depositionprocess, but still taking advantage of the sequential introduction ofprecursors, such a process may be referred to as cyclical CVD. In someembodiments, a cyclical CVD process may comprise the introduction of twoor more precursors into the reaction chamber wherein there may be a timeperiod of overlap between the two or more precursors in the reactionchamber resulting in both an ALD component of the deposition and a CVDcomponent of the deposition. For example, a cyclical CVD process maycomprise the continuous flow of a first precursor and the periodicpulsing of a second precursor into the reaction chamber.

According to some embodiments of the disclosure, ALD processes may beused to form a rhenium-containing film on a substrate, such as anintegrated circuit work piece. In some embodiments, of the disclosure,each ALD cycle may comprise two or more distinct deposition steps orstages. In a first stage of the deposition cycle (“the rhenium stage”),the substrate surface on which deposition is desired may be contactedwith a first vapor phase reactant comprising a rhenium precursor whichchemisorbs on to the surface of the substrate, forming no more thanabout one monolayer of reactant species on the surface of the substrate.In a second stage of the deposition the substrate surface on whichdeposition is desired may be contacted with a second vapor phasereactant comprising at least one of an oxygen containing precursor, asulfur containing precursor, a boron containing precursor, or a hydrogencontaining precursor. Additional stages may comprise, an oxidationstage, a reduction stage, and/or a pre-cleaning stage.

In some embodiment of the disclosure, a specific oxide of rhenium may beselectively deposited over the surface of another composition of rheniumoxide. Such selective oxidation can be controlled by specificallychoosing the oxidative environment. In some embodiments, a certainoxidative environment may be periodically applied to the cyclicaldeposition process.

In some embodiments of the disclosure, a reduction stage may be appliedto the cyclical deposition process. In such embodiments, the reductionstage may be necessary to maintain a specific oxidation state of therhenium in the rhenium-containing film, wherein the rhenium-containingfilm may contain, but is not limited to, rhenium, oxygen, carbon,hydrogen, nitrogen, a halide, phosphorus, sulfur, or boron.

Exemplary Cyclical Deposition Processes for the Formation of RheniumOxide Films

In some embodiments of disclosure, a cyclical deposition process may beutilized to form a rhenium oxide, such as, for example, at least one ofrhenium (IV) oxide (ReO₂), rhenium trioxide (ReO₃), rhenium (VII) oxide(Re₂O₇), or a rhenium oxide having the general formula Re_(a)O_(b),wherein a and b have a value less than 7. In some embodiments, therhenium oxide may comprise a sub-oxide with the general formula ReO_(x)wherein x may be less than 2.

In some embodiments, the cyclical deposition process may compriseforming the rhenium oxide film by the surface reaction between a firstvapor phase reactant and a second vapor phase reactant. In someembodiments, the cyclical deposition process may comprise forming anintermediate rhenium oxide film followed by contacting the intermediaterhenium oxide film with a reducing agent precursor to form a rheniumoxide film of the desired composition. In some embodiments, the cyclicaldeposition process may comprise forming an intermediate rhenium oxidefilm followed by contacting the intermediate rhenium oxide film with anadditional oxygen containing precursor to form a rhenium oxide film ofthe desired composition.

An exemplary rhenium oxide film formation process may be understood withreference to FIG. 1 which illustrates an exemplary cyclical depositionprocess 100 for the formation of a rhenium oxide film.

In more detail, FIG. 1 illustrates an exemplary rhenium oxide formationprocess 100 including a cyclical deposition phase 105. The exemplaryrhenium oxide formation process 100 may commence with a process block110 which comprises, providing a substrate into a reaction chamber andheating the substrate to a desired deposition temperature.

In some embodiments of the disclosure, the substrate may comprise aplanar substrate or a patterned substrate including high aspect ratiofeatures, such as, for example, trench structures and/or fin structures.The substrate may comprise one or more materials including, but notlimited to, silicon (Si), germanium (Ge), germanium tin (GeSn), silicongermanium (SiGe), silicon germanium tin (SiGeSn), silicon carbide (SiC),or a group III-V semiconductor material, such as, for example, galliumarsenide (GaAs), gallium phosphide (GaP), or gallium nitride (GaN). Insome embodiments of the disclosure, the substrate may comprise anengineered substrate wherein a surface semiconductor layer is disposedover a bulk support with an intervening buried oxide (BOX) disposedthere between. In some embodiments liners may be used and may comprisefor example metals, metal nitrides, metal borides, metal carbides, metalphosphides, or metal sulfides. In some embodiments, the liner maycomprise at least one of titanium nitride, tantalum nitride, tantalumcarbide, tungsten carbide, molybdenum, niobium boride, or niobiumcarbide.

Patterned substrates may comprise substrates that may includesemiconductor device structures formed into or onto a surface of thesubstrate, for example, a patterned substrate may comprise partiallyfabricated semiconductor device structures, such as, for example,transistors and/or memory elements. In some embodiments, the substratemay contain monocrystalline surfaces and/or one or more secondarysurfaces that may comprise a non-monocrystalline surface, such as apolycrystalline surface and/or an amorphous surface. Monocrystallinesurfaces may comprise, for example, one or more of silicon (Si), silicongermanium (SiGe), germanium tin (GeSn), or germanium (Ge).Polycrystalline or amorphous surfaces may include dielectric materials,such as oxides, oxynitrides or nitrides, such as, for example, siliconoxides and silicon nitrides.

The reaction chamber utilized for the deposition may be an atomic layerdeposition reaction chamber, or a chemical vapor deposition reactionchamber, or any of the reaction chambers as previously described herein.In some embodiments of the disclosure, the substrate may be heated to adesired deposition temperature for the subsequent cyclical depositionphase 105. For example, the substrate may be heated to a substratetemperature of less than approximately 750° C., or less thanapproximately 650° C., or less than approximately 550° C., or less thanapproximately 450° C., or less than approximately 350° C., or less thanapproximately 250° C., or even less than approximately 150° C. In someembodiments of the disclosure, the substrate temperature during thecyclical deposition phase may be between 300° C. and 750° C., or between400° C. and 600° C., or between 400° C. and 450° C. In some embodiments,the substrate temperature during the cyclical deposition phase may bebetween 80° C. and 150° C., or between 150° C. and 200° C., or evenbetween 200° C. and 350° C.

Upon heating the substrate to a desired deposition temperature, theexemplary rhenium oxide formation process 100 may continue with acyclical deposition phase 105 by means of a process block 120, whichcomprises contacting the substrate with a first vapor phase reactant andparticularly, in some embodiments, contacting the substrate with a firstvapor phase reactant comprising a rhenium vapor phase reactant, i.e.,the rhenium precursor.

In some embodiments of the disclosure, the rhenium precursor maycomprise a rhenium halide precursor. In some embodiments, the rheniumhalide precursor may have an oxidation state of either 4, or 5, or 6, or7. In some embodiments, the rhenium halide precursor may comprise atleast one of a rhenium chloride, a rhenium fluoride, a rhenium bromide,or a rhenium iodide. In some embodiments, the first vapor phase reactantmay comprise a rhenium chloride, such as, for example, rheniumhexachloride (ReCl₆), or rhenium pentachloride (ReCl₅). In someembodiments, the first vapor phase reactant may comprise a rheniumbromide, such as, for example, rhenium pentabromide (ReBr₅). In someembodiments, the first vapor phase reactant may comprise a rheniumfluoride, such as, for example, rhenium pentafluoride (ReF₅), rheniumheptafluoride (ReF₇), or rhenium hexafluoride (ReF₆).

In some embodiments of the disclosure, the rhenium precursor maycomprise a rhenium oxyhalide precursor, wherein the term “rheniumoxyhalide precursor” may refer to a molecule having the general formulaRe_(a)O_(b)X_(c) wherein Re is rhenium, O is oxygen, X is a halogenatom, such as, for example, fluorine (F), chlorine (Cl), bromine (Br),or iodine (I), and a, b, and c, are integers equal to 1 or greater.

In some embodiments, the rhenium oxyhalide may comprise variousoxidation states. For example, the oxidation state of the rhenium in therhenium oxyhalide can be either 2, or 3, or 4, or 5, or 6, or even 7. Insome embodiments, the rhenium oxyhalide may comprise one, two, or threeneutral ligands. For example, the neutral ligands can be alkyl or arylamines, alkyl or aryl phosphines, or cyclic amines, such as, pyridine,for example. In some embodiments, the rhenium oxyhalide may comprise,oxotrichloro bis(triphenylphosphine) rhenium(V) ReOCl₃[PPh₃]2,oxotrichloro bis(trimethylphosphine) rhenium(V) ReOCl₃[(CH3)₃P]₂, oroxotrichloro bis(dimethylamino) rhenium(V) ReOCl₃[(Me₂NH)]_(2.) In someembodiments, the rhenium precursor may comprise a rhenium oxyfluoride,including, but not limited to, rhenium oxyfluoride (ReOF), rheniumtrioxyfluoride (ReO₃F), rhenium oxytetrafluoride (ReOF₄), rheniumoxypentafluoride (ReOF₅), or rhenium dioxydifluoride (ReO₂F₂). In someembodiments, the rhenium precursor may comprise a rhenium oxychloride,including, but not limited to, rhenium oxychloride (ReOCl), rheniumtrioxychloride (ReO₃Cl), or rhenium dioxy dichloride (ReO₂Cl₃).

In some embodiments, the rhenium precursor may comprise an alkyl rheniumoxide, such as, an alkyl rhenium trioxide (RReO₃, wherein R is an alkylgroup). In some embodiments, the alkyl rhenium oxide precursor maycomprise methyl rhenium trioxide (CH₃ReO₃).

In some embodiments, the rhenium precursor may comprise acyclopentadienyl based rhenium precursor. In some embodiments, thecyclopentadienyl based rhenium precursor may comprise at least one of acyclopentadienyl rhenium hydride, a pentacarbonyl hydridorheniumReH[CO]₅, a cyclopentadienyl rhenium carbonyl, or a dirheniumdecacarbonyl Re₂[CO]₁₀. In some embodiments, the cyclopentadienylrhenium hydride precursor may comprise ReHCp₂. In some embodiments, thecyclopentadienyl rhenium carbonyl may have an oxidation state of either1, or 2, or 3, or 4, or 5, or 6. For example, the cyclopentadienylrhenium carbonyl may comprise ReCp[CO]₃, amino cylopentadienylrheniumcarbonyl Re(C₅H₄NH₂)(CO)₃, or Re[C₅Me₅][CO]₃.

In some embodiments, the rhenium precursor may comprise a rheniumcarbonyl halide precursor having the general formula ReX_(a)[CO]_(b)with an oxidation state of either 1, or 2 or 3, or 4, or 5, or 6,wherein X can be fluorine, bromine, chlorine, or iodine, and ‘a’, ‘b’can be greater than or equal to 1. In some embodiments, the rheniumcarbonyl halide precursor may comprise, chloropentacarbonylrhenium (I)ReCl[CO]₅), or bromopentacarbonylrhenium (I) ReBr[CO]₅.

In some embodiments of the disclosure, the metal precursor may beselected to deposit a metal and metal alloy by the selection of thesecond reactant and/or by changing the processing conditions. In someembodiments, the second reactant can be a hydrogen or a nitrogencontaining precursor, such as, for example, hydrogen gas, ammonia, analkyl amine, an ammonia-hydrogen mixture, a nitrogen-hydrogen plasma, ahydrogen plasma, or a boron containing precursor, such as, a borane, analkyl borate, or a carbon containing precursor, such as, for example, analkyl halide, an organic mixed halide, a saturated or unsaturated aswell as aliphatic or non-aliphatic alkane, or a phosphorus containingprecursor, such as, for example, phosphine (PH₃), or alkylphosphines.

In some embodiments, an organic mixed halide is of general formC_(a)X_(b)Y_(d), whereas C is carbon, and X, Y are halides such aschlorine or bromine or iodine or fluorine and a, b, d are integers morethan 1.

In some embodiments of the disclosure, contacting the substrate with afirst vapor phase reactant comprising a rhenium precursor may comprisecontacting the rhenium precursor to the substrate for a time period ofbetween about 0.01 seconds and about 60 seconds, between about 0.05seconds and about 10 seconds, or between about 0.1 seconds and about 5.0seconds. In addition, during the contacting of the substrate with therhenium precursor, the flow rate of the rhenium precursor may be lessthan 2000 sccm, or less than 500 sccm, or even less than 100 sccm. Inaddition, during the contacting of the rhenium precursor to thesubstrate the flow rate of the rhenium precursor may range from about 1to 2000 sccm, from about 5 to 1000 sccm, or from about 10 to about 500sccm.

The exemplary rhenium oxide formation process 100 of FIG. 1 may continueby purging the reaction chamber. For example, excess first vapor phasereactant and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess first vapor phasereactant, such as, for example, excess rhenium precursor and anypossible reaction byproducts may be removed with the aid of a vacuum,generated by a pumping system in fluid communication with the reactionchamber.

Upon purging the reaction chamber with a purge cycle the exemplaryrhenium oxide formation process 100 may continue with a second stage ofthe cyclical deposition phase 105 by means of a process block 130 whichcomprises, contacting the substrate with a second vapor phase reactant,and particularly contacting the substrate with a second vapor phasereactant comprising an oxygen containing precursor (“the oxygenprecursor”).

In some embodiments, the oxygen containing precursor may comprise atleast one of oxygen, ozone (O₃), an oxygen plasma, hydrogen peroxide(H₂O₂), water (H₂O), or formic acid. In some embodiments, the rheniumprecursor may comprise rhenium oxydifluoride (ReOF₂), or rheniumdioxydichloride (ReOCl₂), and the second vapor phase reactant maycomprise water (H₂O), ozone (O₃), or hydrogen peroxide (H₂O₂). In someembodiments, the rhenium precursor may comprise rhenium oxytetrafluoride(ReOF₄), or rhenium oxytetrachloride (ReOCl₄), and the second vaporphase reactant may comprise water (H₂O), ozone (O₃) or hydrogen peroxide(H₂O₂).

In some embodiments of the disclosure, the oxygen containing precursormay comprise at least one of water (H₂O), ozone (O₃), hydrogen peroxide(H₂O₂), molecular oxygen (O₂), atomic oxygen (O), sulfur trioxide (SO₃),or an oxygen based plasma, wherein the oxygen based plasma comprisesatomic oxygen (O), oxygen ions, oxygen radicals, and excited oxygenspecies, and may be generated by the excitation (e.g., by application ofRF power) of an oxygen containing gas. It should be noted that as usedherein the term “vapor phase reactant” includes an excited plasma andthe excited species comprising the plasma.

In some embodiments of the disclosure, contacting the substrate with theoxygen containing precursor may comprise, contacting the oxygenprecursor to the substrate for a time period of between about 0.01seconds and about 60 seconds, between about 0.05 seconds and about 10seconds, or between about 0.1 seconds and about 5.0 seconds. Inaddition, during the contacting of the substrate with the oxygenprecursor, the flow rate of the oxygen precursor may be less than 2000sccm, or less than 500 sccm, or even less than 100 sccm. In addition,during the contacting of the oxygen precursor to the substrate the flowrate of the oxygen precursor may range from about 1 to 2000 sccm, fromabout 5 to 1000 sccm, or from about 10 to about 500 sccm.

Upon contacting the substrate with the oxygen precursor, the exemplaryrhenium oxide formation process 100 may proceed by purging the reactionchamber. For example, excess oxygen precursor and reaction byproducts(if any) may be removed from the surface of the substrate, e.g., bypumping whilst flowing an inert gas. In some embodiments of thedisclosure, the purge process may comprise purging the substrate surfacefor a time period of between approximately 0.1 seconds and approximately10 seconds, or between approximately 0.5 seconds and approximately 3seconds, or even between approximately 1 second and 2 seconds.

Upon completion of the purge of the second vapor phase reactant, i.e.,the oxygen precursor (and any reaction byproducts) from the reactionchamber, the cyclic deposition phase 105 of exemplary rhenium oxideformation process 100 may continue with a decision gate 140, wherein thedecision gate 140 is dependent on the thickness of the rhenium oxidefilm deposited. For example, if the rhenium oxide film is deposited atan insufficient thickness for a desired device application, then thecyclical deposition phase 105 may be repeated by returning to theprocess block 120 and continuing through a further deposition cycle,wherein a unit deposition cycle may comprise, contacting the substratewith a rhenium precursor (process block 120), purging the reactionchamber, contacting the substrate with an oxygen containing precursor(process block 130), and again purging the reaction chamber. A unitdeposition cycle of cyclical deposition phase 105 may be repeated one ormore times until a desired thickness of a rhenium oxide film isdeposited over the substrate. Once the rhenium oxide film has beendeposited to the desired thickness the exemplary process 100 may exitvia a process block 150 and the substrate, with the rhenium oxide filmdeposited thereon, may be subjected to further processing for theformation of a device structure.

It should be appreciated that in some embodiments of the disclosure, theorder of contacting of the substrate with the first vapor phase reactant(e.g., the rhenium precursor) and the second vapor phase reactant (e.g.,the oxygen precursor) may be such that the substrate is first contactedwith the second vapor phase reactant followed by the first vapor phasereactant. In addition, in some embodiments, the cyclical depositionphase 105 of exemplary process 100 may comprise, contacting thesubstrate with the first vapor phase reactant one or more times prior tocontacting the substrate with the second vapor phase reactant one ormore times. In addition, in some embodiments, the cyclical depositionphase 105 of exemplary process 100 may comprise, contacting thesubstrate with the second vapor phase reactant one or more times priorto contacting the substrate with the first vapor phase reactant one ormore times.

As a non-limiting example, the reaction chamber may comprise an ALDreactor and the substrate may be heated to a temperature ofapproximately 200° C. (process block 110). The substrate may then besubjected to one or more deposition cycles of the cyclical depositionphase 105 which may comprise, contacting the substrate with ReOF₂, orReOF₄, and subsequently contacting the substrate with water vapor, orozone, thereby forming a rhenium trioxide (ReO₃) film.

As a further non-limiting example, the reaction chamber may comprise anALD reactor and the substrate may be heated to a temperature ofapproximately 180° C. (process block 110). The substrate may then besubjected to one or more deposition cycles of cyclical deposition phase105 which may comprise, contacting the substrate with ReOF₅ andsubsequently contacting the substrate with water vapor, thereby formingrhenium(VII) oxide (Re₂O₇) films.

In some embodiments, the substrate may then be subjected to one or moredeposition cycles of cyclical deposition phase 105 which may comprise,contacting the substrate with ReOCl, or ReOF, and subsequentlycontacting the substrate with oxygen, ozone, hydrogen peroxide, or watervapor, thereby forming rhenium (IV) oxide (ReO₂) films.

An additional exemplary rhenium oxide formation process may beunderstood with reference to FIG. 2 which illustrates a cyclicaldeposition process 200 for forming a rhenium oxide film.

In more detail, the cyclical deposition process 200 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 200.

Upon heating the substrate to the desired deposition temperature, withina suitable reaction chamber, the cyclical deposition process 200 maycontinue with the cyclical deposition phase 105 comprising, cyclicallydepositing a rhenium oxide film to a desired thickness. The cyclicaldeposition phase 105 for depositing a rhenium oxide film has beendescribed in detail previously with reference to FIG. 1 (exemplaryprocess 100) and therefore described in abbreviated form with respect tocyclical deposition process 200. In more detail, cyclical depositionphase 105 may comprise one or more cyclical deposition cycles, wherein aunit deposition cycle comprises, contacting the substrate with a rheniumprecursor, purging the reaction chamber of excess rhenium precursor andany reaction by-products, contacting the substrate with an oxygencontaining precursor, and purging the reaction chamber of excess oxygenprecursor and any reaction by-products.

As a non-limiting example, the cyclical deposition phase 105 maycomprise contacting the substrate with a rhenium oxyfluoride, such as,for example ReOF₅, and contacting the substrate with water vapor (H₂O)thereby depositing a rhenium oxide film, such as, for example, rhenium(VII) oxide (Re₂O₇).

In some embodiments, an intermittent reduction stage, i.e., contactingthe deposited rhenium oxide film with a reducing agent precursor, can beapplied after depositing a certain thickness of the rhenium oxide film.For example, a reduction stage may be applied to the rhenium oxide filmafter depositing a thickness of rhenium oxide of approximately 0.5Angstroms, or after depositing less than 1 nanometer, or afterdepositing less than 3 nanometers, or after depositing less than orequal to 5 nanometers, or even after depositing greater than 5nanometers.

As a further non-limiting example, the cyclical deposition phase 105 maycomprise contacting the substrate with a rhenium oxyfluoride, such as,for example ReOF₄, and contacting the substrate with water vapor (H₂O)thereby depositing a rhenium oxide film, such as, for example, rheniumtrioxide (ReO₃).

In some embodiments of the disclosure, the cyclical deposition phase 105may be utilized to deposit a rhenium oxide film to a thickness of lessthan 1 Angstrom, or less than 2 Angstrom, or less than 5 Angstrom, orless than 10 Angstroms, or even less than 100 Angstroms. In someembodiments of the disclosure, the cyclical deposition phase 105 may beutilized to deposit a rhenium oxide film to a thickness which may beentirely reduced by subsequently contacting the rhenium oxide film witha reducing agent precursor (“the reducing stage”), whereas in somealternative embodiments the cyclical deposition phase 105 may beutilized to deposit a rhenium oxide to a thickness which may be onlypartially reduced by subsequently contacting the rhenium oxide film witha reducing agent precursor.

Upon forming a rhenium oxide film to a desired thickness the exemplaryprocess 200 may proceed by means of a process block 220 comprising,contacting the substrate, and particularly contacting the rhenium oxidefilm, with a reducing agent precursor. In some embodiments, the reducingagent precursor may comprise a dione, such as, for example,2,5-Hexanedione, cyclohexene-1,4-dione, or cyclohexane dione. In someembodiments the reducing agent precursor may comprise an acid, orcarboxylic acid, such as, for example, glyoxylic acid (OCHCO₂H), formicacid (HCOOH), hydrogen halides like HCl, HF, HI, HBr, or oxalic acid(COOH)₂. In some embodiments, the reducing agent precursor may comprisean ethylene oxide (C₂H₄O), or ethylene carbonate. In some embodimentsthe reducing agent precursor may comprise anhydrides, such as, but notlimited to, acetic anhydride (CH₃CO)₂O, phthalic anhydride, or maleicanhydride C₂H₂(CO)₂O. In some embodiments, the reducing agent precursormay comprise carbon monoxide (CO), nitrogen monoxide (NO), sulfurmonoxide (SO), sulfur dioxide (SO₂), hydrogen (H₂), hydrazine (N₂H₄),forming gas (H₂+N₂), ammonia (NH₃), or an ammonia-hydrogen (NH₃−H₂)mixture.

In some embodiments of the disclosure, contacting the substrate with areducing agent precursor may comprise contacting the reducing agentprecursor to the substrate for a time period of between about 0.01seconds and about 60 seconds, between about 0.05 seconds and about 10seconds, or between about 0.1 seconds and about 5.0 seconds. Inaddition, during the contacting of the substrate with the reducing agentprecursor, the flow rate of the reducing agent precursor may be lessthan 2000 sccm, or less than 500 sccm, or even less than 100 sccm. Inaddition, during the contacting of the reducing agent precursor to thesubstrate the flow rate of the reducing agent precursor may range fromabout 1 to 2000 sccm, from about 5 to 1000 sccm, or from about 10 toabout 500 sccm.

As a non-limiting example, the cyclical deposition phase 105 ofexemplary process 200 may deposit a rhenium (VII) oxide (Re₂O₇) film toa thickness of approximately less than 100 Angstroms and subsequentlythe rhenium (VII) oxide (Re₂O₇) film may be contacted with a reducingagent precursor, such as, but not limited, to carbon monoxide (CO), fora time period greater than 1 second at a substrate temperature of lessthan 250° C., or for a time period greater than 100 seconds at asubstrate temperature of less than 350° C. For example, the reducingagent precursor may comprise a carbon monoxide (CO), a nitrogen monoxide(NO), or a sulfur monoxide (SO) vapor, which may contact the rhenium(VII) oxide (Re₂O₇) film thereby reducing the film to form a rheniumtrioxide (ReO₃) film.

As a further non-limiting example, the cyclical deposition phase 105 ofexemplary process 200 may deposit a rhenium trioxide (ReO₃) film to athickness of approximately less than 1000 Angstroms, or less than lessthan 500 Angstroms, or less than 100 Angstroms, or less than 10Angstroms, or even less than 1 Angstrom and subsequently the rheniumtrioxide (ReO₃) film may be contacted with a reducing agent precursor,such as, but not limited to, carbon monoxide (CO), nitrogen monoxide(NO), glyoxylic acid (OCHCO₂H), 2,5-Hexanedione, cyclohexene-1,4-dione,cyclohexane dione, sulfur dioxide (SO₂), formic acid (HCOOH), aceticanhydride (CH₃CO)₂O, oxalic acid (COOH)₂ or maleic anhydride C₂H₂(CO)₂O,for a time period of less than 5 minutes, or less than 1 minute, or evenless than 10 seconds, at a substrate temperature greater than 60° C., orat a substrate temperature greater than 120° C., or at a substratetemperature greater than 180° C., or even at a substrate temperaturegreater than 250° C. For example, the reducing agent precursor maycomprise a nitrogen monoxide (NO) vapor which may contact the rheniumtrioxide (ReO₃) film thereby reducing the film to form a rhenium (IV)oxide (ReO₂) film.

In some embodiments, the entirety of the rhenium oxide film deposited bythe cyclical deposition phase 105 may be reduced by the contacting therhenium oxide film with the reducing agent precursor, whereas in somealternative embodiments of the disclosure only a portion of the rheniumoxide film deposited by the cyclical deposition phase 105 may be reducedby contacting the rhenium oxide film with the reducing agent precursor.

Upon contacting the substrate with the reducing agent precursor, theexemplary rhenium oxide formation process 200 may proceed by purging thereaction chamber. For example, excess reducing agent precursor andreaction byproducts (if any) may be removed from the surface of thesubstrate, e.g., by pumping whilst flowing an inert gas. In someembodiments of the disclosure, the purge process may comprise purgingthe substrate surface for a time period of between approximately 0.1seconds and approximately 10 seconds, or between approximately 0.5seconds and approximately 3 seconds, or even between approximately 1second and 2 seconds.

Upon completion of the purge of the excess reducing agent precursor (andany reaction byproducts) from the reaction chamber, the exemplaryrhenium oxide formation process 200 may continue with a decision gate240, wherein the decision gate 240 is dependent on the thickness of therhenium oxide film formed. For example, if the rhenium oxide film isformed at an insufficient thickness for a desired device application,then the cyclical deposition phase 205 of exemplary process 200 may berepeated by returning to the cyclical deposition phase 105 andcontinuing through one or more cyclical deposition cycles 205, wherein aunit deposition cycle of the cyclical deposition phase 205 may comprise,cyclically depositing a rhenium oxide film to a desired thickness(cyclical deposition phase 105), purging the reaction chamber,contacting the substrate with a reducing agent precursor (process block220), and again purging the reaction chamber. A unit deposition cycle ofcyclical deposition phase 205 may be repeated one or more times until adesired thickness of a rhenium oxide film with the desired compositionis formed over the substrate. Once the rhenium oxide film has beenformed to the desired thickness and composition the exemplary process200 may exit via a process block 250 and the substrate, with the rheniumoxide film formed thereon, may be subjected to further processing forthe formation of a device structure.

A further exemplary rhenium oxide formation process may be understoodwith reference to FIG. 3 which illustrates a cyclical deposition process300 for forming a rhenium oxide film.

In more detail, the cyclical deposition process 300 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 300.

Upon heating the substrate to the desired deposition temperature withina suitable reaction chamber, the cyclical deposition process 300 maycontinue by utilizing either cyclical deposition phase 105 (of process100, FIG. 1) or cyclical deposition phase 205 (of process 200, FIG. 2).Both cyclical deposition phase 105 and cyclical deposition phase 205have been described in detail previously and therefore described inabbreviated form with respect to cyclical deposition process 300.

In more detail, in some embodiments, the cyclical deposition phase 105may be utilized to deposit a rhenium oxide to a desired thickness andcomposition and may comprise one or more unit cycles of the cyclicaldeposition phase 105 wherein a unit cycle may comprise, contacting thesubstrate with a rhenium precursor, purging the reaction chamber ofexcess rhenium precursor and any reaction by-products, contacting thesubstrate with an oxygen containing precursor, and purging the reactionchamber of excess oxygen precursor and any reaction by-products. In somealternative embodiments, the cyclical deposition phase 205 may beutilized to deposit a rhenium oxide to a desired thickness andcomposition and may comprise one or more unit cycles of the cyclicaldeposition phase 205 wherein a unit cycle may comprise, cyclicallydepositing a rhenium oxide film to a desired thickness, purging thereaction chamber of excess precursor and any reaction by-products,contacting the substrate with a reducing agent precursor, and purgingthe reaction chamber of excess reducing agent precursor and any reactionby-products.

As a non-limiting example, the cyclical deposition phase 105 may beutilized by contacting the substrate with a rhenium oxyfluoride, suchas, for example ReOF₄, and contacting the substrate with water vapor(H₂O) thereby depositing a rhenium oxide film, such as, for example,rhenium trioxide (ReO₃).

As a further non-limiting example, the cyclical deposition phase 205 maybe utilized to form a rhenium oxide film, e.g., a rhenium trioxide(ReO₃), to a desired thickness, and contacting the rhenium trioxide(ReO₃) with a reducing agent precursor thereby forming a rhenium (IV)oxide (ReO₂) film to a desired thickness.

In some embodiments of the disclosure, the cyclical deposition phases105 and 205 may be utilized to form a rhenium oxide film to a thicknessof less than 1000 Angstroms, or less than 500 Angstroms, or less than100 Angstroms, or even less than 10 Angstroms. In some embodiments ofthe disclosure, the cyclical deposition phases 105 and 205 may beutilized to deposit a rhenium oxide film to a thickness which may beentirely oxidized by subsequently contacting the rhenium oxide film withan additional oxygen containing precursor, whereas in some alternativeembodiments the cyclical deposition phases 105 and 205 may be utilizedto form a rhenium oxide to a thickness which may be only partiallyoxidized by subsequently contacting the rhenium oxide film with anadditional oxygen containing precursor.

Upon forming a rhenium oxide film to a desired thickness andcomposition, the exemplary process 300 may proceed by means of a processblock 320 comprising, contacting the substrate, and particularlycontacting the rhenium oxide film, with an additional oxygen containingprecursor.

In some embodiments of the disclosure, the additional oxygen containingprecursor may comprise at least one of water (H₂O), ozone (O₃), formicacid (CH₂O₂), hydrogen peroxide (H₂O₂), molecular oxygen (O₂), atomicoxygen (O), sulfur trioxide (SO₃), or an oxygen based plasma, whereinthe oxygen based plasma comprises atomic oxygen (O), oxygen ions, oxygenradicals, and excited oxygen species, and may be generated by theexcitation (e.g., by application of RF power) of an oxygen containinggas. It should be noted that as used herein the term “vapor phasereactant” includes an excited plasma and the excited species comprisingthe plasma.

In some embodiments of the disclosure, contacting the substrate with theadditional oxygen containing precursor may comprise, contacting theadditional oxygen precursor to the substrate for a time period ofbetween about 0.01 seconds and about 60 seconds, between about 0.05seconds and about 10 seconds, or between about 0.1 seconds and about 5.0seconds. In addition, during the contacting of the additional oxygenprecursor with the substrate, the flow rate of the additional oxygenprecursor may be less than 2000 sccm, or less than 500 sccm, or evenless than 100 sccm. In addition, during the contacting of the additionaloxygen precursor to the substrate the flow rate of the additional oxygenprecursor may range from about 1 to 2000 sccm, from about 5 to 1000sccm, or from about 10 to about 500 sccm.

As a non-limiting example, the cyclical deposition phase 105 ofexemplary process 300 may be utilized to deposition a rhenium trioxidefilm (ReO₃) to a thickness of approximately less than 1000 Angstroms, orless than 500 Angstroms, or less than 100 Angstroms, or even less than 1Angstrom and subsequently the rhenium trioxide (ReO₃) film may becontacted with an additional oxygen precursor, such as, for example,oxygen, water, an oxygen containing plasma, ozone, acetic acid, orhydrogen peroxide, for a time period of less than or equal to 10minutes, or less than 1 minute, or even less than 10 seconds, at asubstrate temperature of less than 400° C., or less than 300° C., orless than 200° C., or even less than 100° C. For example, the additionaloxygen containing precursor may comprise ozone (O₃) which may contactthe rhenium trioxide film (ReO₃) thereby oxidizing the film to form arhenium (VII) oxide (Re₂O₇) film.

As an additional non-limiting example, the cyclical deposition phase 105of exemplary process 300 may be utilized to deposition a rhenium (IV)oxide (ReO₂) film to a thickness of approximately less than 1000Angstroms, or less than 500 Angstroms, or less than 100 Angstroms, oreven less than 10 Angstroms and subsequently the rhenium (IV) oxide(ReO₂) film may be contacted with an additional oxygen precursor, suchas, for example, oxygen, water, an oxygen containing plasma, ozone,acetic acid, or hydrogen peroxide, for a time period of less than orequal to 10 minutes, or less than 1 minute, or even less than 10seconds, at a substrate temperature of less than 400° C., or less than300° C., or less than 200° C., or even less than 100° C. For example,the additional oxygen containing precursor may comprise hydrogenperoxide (H₂O₂) which may contact the rhenium (IV) oxide (ReO₂) filmthereby oxidizing the film to form a rhenium (VII) oxide (Re₂O₇) film.

As a further non-limiting example, the cyclical deposition phase 205 ofexemplary process 300 may be utilized to form a rhenium (IV) oxide(ReO₂) film to a thickness of approximately less than 1000 Angstroms, orless than 500 Angstroms, or less than 100 Angstroms, or less than 10Angstroms and subsequently the rhenium (IV) oxide (ReO₂) film may becontacted with an additional oxygen precursor, such as, for example,oxygen, water, an oxygen containing plasma, ozone, acetic acid, orhydrogen peroxide, for a time period of less than or equal to 10minutes, or less than 1 minute, or even less than 10 seconds, at asubstrate temperature of less than 400° C., or less than 300° C., orless than 200° C., or even less than 100° C. For example, the additionaloxygen containing precursor may comprise an oxygen based plasma whichmay contact the rhenium (IV) oxide (ReO₂) film thereby oxidizing thefilm to form a rhenium (VII) oxide (Re₂O₇) film.

Therefore, in some embodiments of the disclosure, the rhenium oxide filmcomprises at least one of a rhenium (IV) oxide (ReO₂) film, or a rheniumtrioxide (ReO₃) film, and the methods of the disclosure furthercomprises contacting the rhenium oxide film with an additional oxygencontaining precursor thereby forming a rhenium (VII) oxide (Re₂O₇) film.

Upon contacting the substrate with the additional oxygen precursor, theexemplary rhenium oxide formation process 300 may proceed by purging thereaction chamber. For example, excess additional oxygen precursor andreaction byproducts (if any) may be removed from the surface of thesubstrate, e.g., by pumping whilst flowing an inert gas. In someembodiments of the disclosure, the purge process may comprise purgingthe substrate surface for a time period of between approximately 1second and approximately 100 seconds, or between approximately 0.1seconds and approximately 10 seconds, or between approximately 0.5seconds and approximately 3 seconds, or even between approximately 1second and 2 seconds.

Upon completion of the purge of the excess additional oxygen precursor(and any reaction byproducts) from the reaction chamber, the exemplaryrhenium oxide formation process 300 may continue with a decision gate340, wherein the decision gate 340 is dependent on the thickness of therhenium oxide film formed. For example, if the rhenium oxide film isformed at an insufficient thickness for a desired device application,then a cyclical deposition phase 305 may be repeated by returning to thecyclical deposition phase 105 or 205 and continuing through cyclicaldeposition phase 305, wherein a unit deposition cycle of the cyclicaldeposition phase 305 may comprise, forming a rhenium oxide film to adesired thickness and composition (cyclical phases 105 or 205), purgingthe reaction chamber, contacting the substrate with an additional oxygencontaining precursor (process block 320), and again purging the reactionchamber. A unit deposition cycle of the cyclical deposition phase 305may be repeated one or more times until a desired thickness of a rheniumoxide film with the desired composition is formed over the substrate.Once the rhenium oxide film has been formed to the desired thickness andcomposition the exemplary process 300 may exit via a process block 350and the substrate, with the rhenium oxide film formed thereon, may besubjected to further processing for the formation of a device structure.

In some embodiments of the disclosure, the rhenium oxide films formed bythe exemplary processes disclosed herein may comprise dielectricmaterials. For example, a rhenium (VII) oxide (Re₂O₇) film, or a rhenium(IV) oxide (ReO₂) film formed by the methods of the disclosure maycomprise a dielectric material.

In some embodiments of the disclosure, the rhenium oxide films formed bythe exemplary processes disclosed herein may comprise a conductiverhenium oxide film. In some embodiments, the conductive phase of therhenium oxide films may comprise rhenium (IV) oxide (ReO₂) films, orrhenium trioxide (ReO₃) films. In some embodiments, the conductiverhenium oxide films may comprise a sub-oxide with the general formulaReO_(x) where x is less than 2. In some embodiments, the conductivephase of the rhenium oxide films formed by the embodiments of thedisclosure may have an electrical resistivity as-deposited of less than1000 μΩ-cm, or less than 700 μΩ-cm, or less than 500 μΩ-cm, or less than250 μΩ-cm, or less than 100 μΩ-cm, or less than 50 μΩ-cm, or less than25 μΩ-cm, or less than 10 μΩ-cm, or even less than 5 μΩ-cm. In someembodiments, the conductive phase of the rhenium oxide films formed byembodiments of the disclosure may have an electrical resistivityas-deposited between 5 μΩ-cm and 1000 μΩ-cm.

In some embodiments of the disclosure, the rhenium oxide films formedaccording to the embodiments of the disclosure may be subjected to oneor more further processes to further improve the electrical resistivityof the rhenium oxide films.

In more detail, FIGS. 4A-4C illustrate cross-sectional schematicdiagrams of semiconductor structures formed utilizing an exemplaryprocess for forming a low resistivity conducting rhenium oxide film. Insome embodiments, the methods of the disclosure may comprise providing asubstrate, such as a substrate 400 of FIG. 4A. Substrate 400 maycomprise a non-planar or planar (as illustrated) and may furthercomprise one or more materials as previously disclosed with reference tothe process block 110 of FIG. 1.

The substrate 400 may be provided into a suitable reaction chamber, suchas, for example, an atomic layer deposition (ALD) reaction chamber andheated to a desired deposition temperature. Upon heating the substrateto the desired deposition temperature a rhenium oxide film 402 (FIG. 4B)may be deposited over the substrate 400 utilizing one of exemplaryprocesses 100 (FIG. 1), 200 (FIG. 2), or 300 (FIG. 3). In someembodiments, the rhenium oxide film 402 comprises a conductive rheniumoxide film. In some embodiments, the conductive rhenium oxide film 402may comprise at least one of rhenium (IV) oxide (ReO₂), or rheniumtrioxide (ReO₃). In some embodiments, the conductive rhenium oxide filmsmay comprise a sub-oxide with the general formula ReO_(x) where x isless than 2. In some embodiments, the conductive rhenium oxide film maybe formed to a thickness of less 1000 Angstroms, or less than 500Angstroms, or less than 250 Angstroms, or less than 100 Angstroms, orless than 50 Angstroms, or even less than 20 Angstroms, and may have anelectrical resistivity of less than 1000 μΩ-cm, or less than 500 μΩ-cm,or less than 100 μΩ-cm, or less than 50 μΩ-cm, or even less than 20μΩ-cm.

In some embodiments of the disclosure, the method of formation of a lowelectrical resistivity conductive rhenium oxide film may furthercomprise forming a capping layer over a surface of the rhenium oxidefilm. For example, a capping layer 404 may be deposited directly overthe upper exposed surface of the rhenium oxide film 402 thereby formingthe semiconductor structure 406, as illustrated in FIG. 4C. In someembodiments, the capping layer 404 may comprise a conductive layer, suchas, for example, titanium nitride (TiN), tantalum nitride (TaN),tantalum (Ta), tungsten carbide (WC), molybdenum (Mo), or niobium boride(NbB). Not to be bound by any particular theory or mechanism, it isbelieved that the addition of a capping layer over the surface of therhenium oxide film may prevent, or substantially prevent, thesublimation of the rhenium oxide film.

Upon deposition of the capping layer 404 over a surface of the rheniumoxide film 402, the methods of the disclosure may further comprisethermally annealing the rhenium oxide film 402. For example, thesemiconductor structure 406 including the rhenium oxide film 402 may bethermally annealed at a temperature greater than 50° C., or greater than100° C., or greater than 200° C., or greater than 300° C., or evengreater than 400° C., or can be in the temperature range between 50° C.and 400° C. In some embodiments, thermally annealing the rhenium oxidefilm 402 may further comprise increasing the grain size of thecrystallites comprising the rhenium oxide film 402. In some embodiments,thermally annealing the rhenium oxide film 402 may further compriseforming a substantially single crystalline rhenium oxide film. In someembodiments, thermally annealing the rhenium oxide film 402 may furthercomprise reducing the density of grain boundaries within the rheniumoxide film. In some embodiments, thermally annealing the rhenium oxidefilm 402 may further comprise reducing the electrical resistivity of therhenium oxide film. For example, the rhenium oxide film post thermalannealing may have an electrical resistivity of less than 1000 μΩ-cm, orless than 100 μΩ-cm, or even less than 10 μΩ-cm.

Exemplary Cyclical Deposition Processes for the Formation of RheniumSulfide Films

In some embodiments of disclosure, a cyclical deposition process may beutilized to form a rhenium sulfide of general formulae ReS_(a) orRe_(x)S_(y) where a, x, and y are less than or equal to 7, such as, forexample, rhenium disulfide (ReS₂), or dirhenium hepta sulfide (Re₂S₇).In some embodiments, the cyclical deposition process may comprise,forming the rhenium sulfide film by the surface reaction between a firstvapor phase reactant and a second vapor phase reactant. In someembodiments, the cyclical deposition process may comprise forming anintermediate rhenium oxide film followed by contacting the intermediaterhenium oxide film with a sulfur containing precursor.

An exemplary rhenium sulfide formation process may be understood withreference to FIG. 5 which illustrates an exemplary cyclical depositionprocess 500 for the forming of a rhenium sulfide film.

In more detail, the cyclical deposition process 500 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 500.

Upon heating the substrate to the desired deposition temperature withina suitable reaction chamber, the cyclical deposition process 500 maycontinue by means of the process of a cyclical deposition phase 505which may commence via a process block 120. The process block 120 hasbeen previously described in detail with reference to FIG. 1 (cyclicaldeposition process 100) and therefore appears in abbreviated form withrespect to cyclical deposition process 500.

In more detail, the process block 120 may comprise contacting thesubstrate with a rhenium precursor. In some embodiments, the rheniumprecursor may comprise a rhenium halide, such as, for example, a rheniumchloride, a rhenium bromide, a rhenium fluoride, or a rhenium iodide. Inparticular embodiments, the rhenium precursor may comprise a rheniumoxyhalide, such as, for example, a rhenium oxychloride, or rheniumoxyfluoride. In some embodiments the rhenium oxyhalide may comprise atleast one of ReOF₄, ReOF₅, ReO₂F₂, or ReO₂Cl₃. In some embodiments, therhenium precursor may comprise an alkyl rhenium oxide precursor; acyclopentadienyl based rhenium precursor, or a rhenium carbonyl halideprecursor.

The exemplary rhenium sulfide formation process 500 of FIG. 5 maycontinue by purging the reaction chamber. For example, excess rheniumprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess rhenium precursorand any possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

The cyclical deposition phase 505 of exemplary rhenium sulfide formationprocess 500 may continue by means of a process block 530 comprising,contacting the substrate with a sulfur containing precursor (“the sulfurprecursor”). In some embodiments, the sulfur containing precursorcomprises at least one of hydrogen sulfide (H₂S), sulfur dioxide (SO₂),carbon disulfide (CS₂), dimethyl sulfide (C₂H₆S), methanethiol (CH₃SH),or a dialkyl disulfide.

In some embodiments of the disclosure, contacting the substrate with thesulfur containing precursor may comprise, contacting the sulfurprecursor to the substrate for a time period of between about 0.01seconds and about 60 seconds, between about 0.05 seconds and about 10seconds, or between about 0.1 seconds and about 5.0 seconds. Inaddition, during the contacting of the substrate with the sulfurprecursor, the flow rate of the sulfur precursor may be less than 2000sccm, or less than 500 sccm, or even less than 100 sccm. In addition,during the contacting of the substrate with the sulfur precursor, theflow rate of the sulfur precursor may range from about 1 to 2000 sccm,from about 5 to 1000 sccm, or from about 10 to about 500 sccm.

The exemplary rhenium sulfide formation process 500 of FIG. 5 maycontinue by purging the reaction chamber. For example, excess sulfurprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess sulfur precursor andany possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

Upon completion of the purge of the excess sulfur precursor (and anyreaction byproducts) from the reaction chamber, the exemplary rheniumsulfide formation process 500 may continue with a decision gate 540,wherein the decision gate 540 is dependent on the thickness of therhenium sulfide film deposited. For example, if the rhenium sulfide filmis deposited at an insufficient thickness for a desired deviceapplication, then the cyclical deposition phase 505 may be repeated byreturning to the process block 120 and continuing through cyclicaldeposition phase 505, wherein a unit deposition cycle of the cyclicaldeposition phase 505 may comprise, contacting the substrate with arhenium oxyhalide precursor (process block 120), purging the reactionchamber, contacting the substrate with a sulfur containing precursor(process block 530), and again purging the reaction chamber. A unitdeposition cycle of cyclical deposition phase 505 may be repeated one ormore times until a desired thickness of a rhenium sulfide film with thedesired composition is formed over the substrate. Once the rheniumsulfide film has been deposited to the desired thickness and compositionthe exemplary process 500 may exit via a process block 550 and thesubstrate, with the rhenium sulfide film formed thereon, may besubjected to further processing for the formation of a device structure.

It should be appreciated that in some embodiments of the disclosure, theorder of contacting of the substrate with the first vapor phase reactant(e.g., the rhenium precursor) and the second vapor phase reactant (e.g.,the sulfur precursor) may be such that the substrate is first contactedwith the second vapor phase reactant followed by the first vapor phasereactant. In addition, in some embodiments, the cyclical depositionphase 505 of exemplary process 500 may comprise, contacting thesubstrate with the first vapor phase reactant one or more times prior tocontacting the substrate with the second vapor phase reactant one ormore times. In addition, in some embodiments, the cyclical depositionphase 505 of exemplary process 500 may comprise, contacting thesubstrate with the second vapor phase reactant one or more times priorto contacting the substrate with the first vapor phase reactant one ormore times.

As a non-limiting example, the reaction chamber may comprise an ALDreactor and the substrate may be heated to a temperature betweenapproximately 100° C. and approximately 400° C. (process block 110). Thesubstrate may then be subjected to one or more deposition cycles ofcyclical deposition phase 505 which may comprise, contacting thesubstrate with ReO₂F₂, and subsequently contacting the substrate withhydrogen sulfide (H₂S), thereby forming a rhenium disulfide (ReS₂) film.

A further exemplary rhenium sulfide formation process may be understoodwith reference to FIG. 6 which illustrates a cyclical deposition process600 for forming a rhenium sulfide film.

In more detail, the cyclical deposition process 600 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 600.

Upon heating the substrate to the desired deposition temperature withina suitable reaction chamber, the cyclical deposition process 600 maycontinue by forming a rhenium oxide film to a desired thickness andcomposition utilizing either the cyclical deposition phase 105 (ofprocess 100, FIG. 1), the cyclical deposition phase 205 (of process 200,FIG. 2), or the cyclical deposition phase 305 (of process 300, FIG. 3).Cyclical deposition phases 105, 205 and 305 have been described indetail previously and therefore the specifics of the cyclical depositionphases 105, 205, and 305 are not repeated with respect to the cyclicaldeposition process 600.

In some embodiments of the disclosure, the cyclical deposition phase105, 205, or 305 may be utilized to form a rhenium oxide film, such as,for example, a rhenium (IV) oxide (ReO₂) film, a rhenium trioxide (ReO₃)film, or a rhenium (VII) oxide (Re₂O₇) film. In some embodiments, therhenium oxide film may be formed to a thickness of less than 1000Angstroms, or less than 500 Angstroms, or less than 250 Angstroms, orless than 100 Angstroms, or even less than 10 Angstroms.

In some embodiments of the disclosure, the rhenium oxide may be formedto a thickness which may be entirely converted to a rhenium sulfide filmon subsequently contacting the rhenium oxide with a sulfur precursor,whereas in some alternative embodiments the rhenium oxide may be formedto a thickness which may be only be partially converted to a rheniumsulfide film on subsequently contacting the rhenium oxide with a sulfurprecursor.

In some embodiments of the disclosure, the cyclical deposition phase 605may continue by means of a process block 620 comprising, contacting thesubstrate with a sulfur containing precursor (“the sulfur precursor”).In some embodiments, the sulfur containing precursor may comprise atleast one of hydrogen sulfide (H₂S), sulfur dioxide (SO₂), carbondisulfide (CS₂), dimethyl sulfide (C₂H₆S), methanethiol (CH₃SH), or adialkyl disulfide.

In some embodiments of the disclosure, contacting the substrate, andparticularly the rhenium oxide film with the sulfur containing precursormay comprise, contacting the sulfur precursor to the substrate for atime period of between about 0.01 seconds and about 60 seconds, betweenabout 0.05 seconds and about 10 seconds, or between about 0.1 secondsand about 5.0 seconds. In addition, during the contacting of thesubstrate with the sulfur precursor, the flow rate of the sulfurprecursor may be less than 2000 sccm, or less than 500 sccm, or evenless than 100 sccm. In addition, during the contacting of the sulfurprecursor to the substrate the flow rate of the sulfur precursor mayrange from about 1 to 2000 sccm, from about 5 to 1000 sccm, or fromabout 10 to about 500 sccm.

The exemplary rhenium sulfide formation process 600 of FIG. 6 maycontinue by purging the reaction chamber. For example, excess sulfurprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess sulfur precursor andany possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

Upon completion of the purge of the excess additional sulfur precursor(and any reaction byproducts) from the reaction chamber, the exemplaryrhenium sulfide formation process 600 may continue with a decision gate640, wherein the decision gate 640 is dependent on the thickness of therhenium sulfide film formed. For example, if the rhenium sulfide film isformed at an insufficient thickness for a desired device application,then the cyclical deposition phase 605 may be repeated by returning tothe either cyclical phase 105, 205, or 305 for forming a rhenium oxidefilm to a desired thickness and composition and continuing through cycledeposition phase 605, wherein a unit deposition cycle of the cyclicaldeposition phase 605 may comprise, forming a rhenium oxide film to adesired thickness and composition (cyclical phases 105, 205, or 305),purging the reaction chamber, contacting the substrate with a sulfurprecursor (process block 640), and again purging the reaction chamber. Aunit deposition cycle of cyclical deposition phase 605 may be repeatedone or more times until a desired thickness of a rhenium sulfide filmwith the desired composition is formed over the substrate. Once therhenium sulfide film has been formed to the desired thickness andcomposition the exemplary process 600 may exit via a process block 650and the substrate, with the rhenium sulfide film formed thereon, may besubjected to further processing for the formation of a device structure.

As a non-limiting example, the cyclical deposition phase 105 may beutilized in cyclical deposition process 600 to deposition a rheniumtrioxide film (ReO₃) to a thickness of approximately less than 300Angstroms and subsequently the rhenium trioxide (ReO₃) film may becontacted with a sulfur precursor, such as, for example, hydrogensulfide (H₂S), sulfur monoxide (SO), sulfur dioxide (SO₂), carbondisulfide (CS₂), dimethyl sulfide (C₂H₆S) or methanethiol (CH₃SH), for atime period of less than 10 minutes, or less than 5 minutes, or lessthan 1 minute, or even less than 10 seconds, at a substrate temperaturein the range between 100° C. and 400° C., or between 150° C. and 300° C.For example, the sulfur containing precursor may comprise hydrogensulfide (H₂S) which may contact the rhenium trioxide film (ReO₃) therebyconverting the rhenium oxide film to form a rhenium disulfide (ReS₂),dirhenium heptasulfide (Re₂S₇) or a rhenium sulfide of general formulaeReS_(a) where a is a non-integer number less than 3.5.

Exemplary Cyclical Deposition Processes for the Formation of ElementalRhenium Films

In some embodiments of disclosure, a cyclical deposition process may beutilized to form an elemental rhenium film. In some embodiments, thecyclical deposition process may comprise forming the elemental rheniumfilm by the surface reaction between a first vapor phase reactant and asecond vapor phase reactant. In some embodiments, the cyclicaldeposition process may comprise forming an intermediate rhenium oxidefilm followed by contacting the intermediate rhenium oxide film with ahydrogen containing precursor thereby forming the elemental rheniumfilm.

An exemplary elemental rhenium formation process may be understood withreference to FIG. 7 which illustrates an exemplary cyclical depositionprocess 700 for the forming of an elemental rhenium film.

In more detail, the cyclical deposition process 700 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 700.

Upon heating the substrate to the desired deposition temperature withina suitable reaction chamber, the cyclical deposition process 700 maycontinue by means of the process of a cyclical deposition phase 705which may commence via a process block 120. The process block 120 hasbeen previously described in detail with reference to FIG. 1 (cyclicaldeposition process 100) and therefore appears in abbreviated form withrespect to cyclical deposition process 700.

In more detail, the process block 120 may comprise contacting thesubstrate with a rhenium precursor. In some embodiments, the rheniumprecursor may comprise a rhenium halide, such as, for example, a rheniumchloride, a rhenium bromide, a rhenium fluoride, or a rhenium iodide. Inparticular embodiments, the rhenium precursor may comprise a rheniumoxyhalide, such as, for example, a rhenium oxychloride, or rheniumoxyfluoride. In some embodiments the rhenium oxyhalide may comprise atleast one of ReOF₄, ReOF₅, ReO₂F₂, or ReO₂Cl₃. In some embodiments, therhenium precursor may comprise, an alkyl rhenium oxide precursor; acyclopentadienyl based rhenium precursor, or a rhenium carbonyl halideprecursor.

The exemplary elemental rhenium formation process 700 of FIG. 7 maycontinue by purging the reaction chamber. For example, excess rheniumprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess rhenium precursorand any possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

The cyclical deposition phase 705 of exemplary elemental rheniumformation process 700 may continue by means of a process block 730comprising, contacting the substrate with a hydrogen containingprecursor (“the hydrogen precursor”). In some embodiments, the hydrogencontaining precursor comprises at least one hydrogen sulfide (H₂S),molecular hydrogen (H₂), atomic hydrogen (H), hydrazine (N₂H₄), forminggas (H₂+N₂), ammonia (NH₃), an ammonia-hydrogen (NH₃−H₂) mixture, or ahydrogen based plasma, wherein the hydrogen based plasma comprisesatomic hydrogen (H), hydrogen ions, hydrogen radicals, and excitedhydrogen species, and may be generated by the excitation (e.g., byapplication of RF power) of a hydrogen containing gas. It should benoted that as used herein the term “vapor phase reactant” includes anexcited plasma and the excited species comprising the plasma.

In some embodiments of the disclosure, contacting the substrate with thehydrogen containing precursor may comprise, contacting the hydrogenprecursor to the substrate for a time period of between about 0.01seconds and about 60 seconds, between about 0.05 seconds and about 10seconds, or between about 0.1 seconds and about 5.0 seconds. Inaddition, during the contacting of the substrate with hydrogenprecursor, the flow rate of the hydrogen precursor may be less than 2000sccm, or less than 500 sccm, or even less than 100 sccm. In addition,during the contacting of the substrate with the hydrogen precursor theflow rate of the hydrogen precursor may range from about 1 to 2000 sccm,from about 5 to 1000 sccm, or from about 10 to about 500 sccm.

The exemplary elemental rhenium formation process 700 of FIG. 7 maycontinue by purging the reaction chamber. For example, excess hydrogenprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess hydrogen precursorand any possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

Upon completion of the purge of the excess hydrogen precursor (and anyreaction byproducts) from the reaction chamber, the exemplary elementalrhenium formation process 700 may continue with a decision gate 740,wherein the decision gate 740 is dependent on the thickness of theelemental rhenium film formed. For example, if the elemental rheniumfilm is formed at an insufficient thickness for a desired deviceapplication, then the cyclical deposition phase 705 may be repeated byreturning to the process block 120 and continuing through cyclicaldeposition phase 705, wherein a unit deposition cycle of the cyclicaldeposition phase 705 may comprise, contacting the substrate with arhenium precursor (process block 120), purging the reaction chamber,contacting the substrate with a hydrogen containing precursor (processblock 730), and again purging the reaction chamber. A unit depositioncycle of cyclical deposition phase 705 may be repeated one or more timesuntil a desired thickness of an elemental rhenium film is formed overthe substrate. Once the elemental rhenium film has been deposited to thedesired thickness the exemplary process 700 may exit via a process block750 and the substrate, with the elemental rhenium film formed thereon,may be subjected to further processing for the formation of a devicestructure.

It should be appreciated that in some embodiments of the disclosure, theorder of contacting of the substrate with the first vapor phase reactant(e.g., the rhenium precursor) and the second vapor phase reactant (e.g.,the hydrogen precursor) may be such that the substrate is firstcontacted with the second vapor phase reactant followed by the firstvapor phase reactant. In addition, in some embodiments, the cyclicaldeposition phase 705 of exemplary process 700 may comprise, contactingthe substrate with the first vapor phase reactant one or more timesprior to contacting the substrate with the second vapor phase reactantone or more times. In addition, in some embodiments, the cyclicaldeposition phase 705 of exemplary process 700 may comprise, contactingthe substrate with the second vapor phase reactant one or more timesprior to contacting the substrate with the first vapor phase reactantone or more times.

As a non-limiting example, the reaction chamber may comprise an ALDreactor and the substrate may be heated to a temperature of betweenapproximately 150° C. and 300° C. (process block 110). The substrate maythen be subjected to one or more deposition cycles of cyclicaldeposition phase 705 which may comprise, contacting the substrate withReO₂F₂, and subsequently contacting the substrate with a hydrogen basedplasma, thereby forming an elemental rhenium film.

A further exemplary elemental rhenium film formation process may beunderstood with reference to FIG. 8 which illustrates a cyclicaldeposition process 800 for forming an elemental rhenium film.

In more detail, the cyclical deposition process 800 may commence with aprocess block 110 comprising, providing a substrate into a reactionchamber and heating the substrate to a deposition temperature. Theprocess block 110 has been described in detail with reference to FIG. 1(cyclical deposition process 100) and therefore the details of theprocess block 110 are not repeated with respect to the cyclicaldeposition process 800.

Upon heating the substrate to the desired deposition temperature withina suitable reaction chamber, the cyclical deposition process 800 maycontinue by forming a rhenium oxide film to a desired thickness andcomposition utilizing either the cyclical deposition phase 105 (ofprocess 100, FIG. 1), the cyclical deposition phase 205 (of process 200,FIG. 2), or the cyclical deposition phase 305 (of process 300, FIG. 3).Cyclical deposition phases 105, 205, and 305 have been described indetail previously and therefore the specifics of the cyclical depositionphases 105, 205, and 305 are not repeated with respect to the cyclicaldeposition process 800.

In some embodiments of the disclosure, the cyclical deposition phase105, 205, or 305 may be utilized to form a rhenium oxide film, such as,for example, a rhenium (IV) oxide (ReO₂) film, a rhenium trioxide (ReO₃)film, or a rhenium (VII) oxide (Re₂O₇) film. In some embodiments, therhenium oxide film may formed to a thickness of less than 1000Angstroms, or less than 500 Angstroms, or less than 100 Angstroms, orless than 10 Angstroms, or even less than 5 Angstroms.

In some embodiments of the disclosure, the rhenium oxide may be formedto a thickness which may be entirely converted to an elemental rheniumfilm by subsequently contacting the rhenium oxide with a hydrogenprecursor, whereas in some alternative embodiments the rhenium oxide maybe formed to a thickness which may only be partially converted to anelemental rhenium film by subsequently contacting the rhenium oxide witha hydrogen precurser.

In some embodiments of the disclosure, the cyclical deposition phase 805may continue by means of a process block 820 comprising, contacting thesubstrate with a hydrogen containing precursor (“the hydrogenprecursor”). In some embodiments, the hydrogen containing precursor maycomprise at least one of hydrogen sulfide (H₂S), hydrazine (N₂H₄),forming gas (H₂+N₂), ammonia (NH₃), an ammonia-hydrogen (NH₃−H₂)mixture, molecular hydrogen (H₂), atomic hydrogen (H), or a hydrogenbased plasma, wherein the hydrogen based plasma comprises atomichydrogen (H), hydrogen ions, hydrogen radicals, and excited hydrogenspecies, and may be generated by the excitation (e.g., by application ofRF power) of a hydrogen containing gas.

In some embodiments of the disclosure, contacting the substrate, andparticularly the rhenium oxide film with the hydrogen containingprecursor may comprise, contacting the hydrogen precursor to thesubstrate for a time period of between about 0.01 seconds and about 60seconds, between about 0.05 seconds and about 10 seconds, or betweenabout 0.1 seconds and about 5.0 seconds. In addition, during thecontacting of the substrate with the hydrogen precursor, the flow rateof the hydrogen precursor may be less than 2000 sccm, or less than 500sccm, or even less than 100 sccm. In addition, during the contacting ofthe substrate with the hydrogen precursor the flow rate of the hydrogenprecursor may range from about 1 to 2000 sccm, from about 5 to 1000sccm, or from about 10 to about 500 sccm.

The exemplary elemental rhenium film formation process 800 of FIG. 8 maycontinue by purging the reaction chamber. For example, excess hydrogenprecursor and reaction byproducts (if any) may be removed from thesurface of the substrate, e.g., by pumping with an inert gas. In someembodiments of the disclosure, the purge process may comprise a purgecycle wherein the substrate surface is purged for a time period of lessthan approximately 5.0 seconds, or less than approximately 3.0 seconds,or even less than approximately 2.0 seconds. Excess hydrogen precursorand any possible reaction byproducts may be removed with the aid of avacuum, generated by a pumping system in fluid communication with thereaction chamber.

Upon completion of the purge of the excess hydrogen precursor (and anyreaction byproducts) from the reaction chamber, the exemplary elementalrhenium formation process 800 may continue with a decision gate 840,wherein the decision gate 840 is dependent on the thickness of theelemental rhenium film formed. For example, if the elemental rheniumfilm is formed at an insufficient thickness for a desired deviceapplication, then the cyclical deposition phase 805 may be repeated byreturning to the either cyclical phase 105, 205, or 305 for forming arhenium oxide film to a desired thickness and composition and continuingthrough deposition cycle phase 805, wherein a unit deposition cycle ofthe cyclical deposition phase 805 may comprise, forming a rhenium oxidefilm to a desired thickness and composition (cyclical phases 105, 205,or 305), purging the reaction chamber, contacting the substrate with ahydrogen precursor (process block 820), and again purging the reactionchamber. A unit deposition cycle of cyclical deposition phase 805 may berepeated one or more times until a desired thickness of an elementalrhenium film is formed over the substrate. Once the elemental rheniumfilm has been formed to the desired thickness the exemplary process 800may exit via a process block 850 and the substrate, with the elementalrhenium film formed thereon, may be subjected to further processing forthe formation of a device structure.

As a non-limiting example, the cyclical deposition phase 105 may beutilized in cyclical deposition process 800 to deposition a rheniumtrioxide film (ReO₃) to a thickness of approximately less than 200Angstroms and subsequently the rhenium trioxide (ReO₃) film may becontacted with a hydrogen precursor, such as, for example, hydrogendiatomic gas (H₂), a hydrogen containing plasma, ammonia (NH₃) anammonia-hydrogen mixture (NH₃−H₂), or forming gas (H₂−N₂) for a timeperiod of less than 10 minutes, or less than 5 minutes, or less than 1minute, or even less than 10 seconds, at a substrate temperature in thetemperature range between 80° C. and 400° C. For example, the hydrogencontaining precursor may comprise a hydrogen based plasma which maycontact the rhenium trioxide film (ReO₃) thereby converting the oxidefilm to form an elemental rhenium film.

Properties of Rhenium-Containing Films Formed by Cyclical DepositionProcesses

In some embodiments of the disclosure, the growth rate of therhenium-containing film, e.g., elemental rhenium films, rhenium oxidefilms, rhenium boride films, or rhenium sulfide films, may be from about0.005 Angstroms/cycle to about 5 Angstroms/cycle, from about 0.01Angstroms/cycle to about 2.0 Angstroms/cycle. In some embodiments, thegrowth rate of the rhenium-containing film may be from about 0.1Angstroms/cycle to about 10 Angstroms/cycle. In some embodiments thegrowth rate of the rhenium-containing film is more than about 0.05Angstroms/cycle, more than about 0.1 Angstroms/cycle, more than about0.15 Angstroms/cycle, more than about 0.20 Angstroms/cycle, more thanabout 0.25 Angstroms/cycle, or even more than about 0.3 Angstroms/cycle.In some embodiments the growth rate of the rhenium-containing film isless than about 2.0 Angstroms/cycle, less than about 1.0Angstroms/cycle, less than about 0.75 Angstroms/cycle, less than about0.5 Angstroms/cycle, or less than about 0.2 Angstroms/cycle. In someembodiments of the disclosure, the rhenium-containing film may bedeposited at a growth rate of approximately less than 2.5Angstroms/cycle, or even less than 1 Angstroms/cycle.

The rhenium-containing films deposited by the methods disclosed hereinmay be continuous films. In some embodiments, the rhenium-containingfilm may be continuous at a thickness below approximately 100 Angstroms,or below approximately 60 Angstroms, or below approximately 50Angstroms, or below approximately 40 Angstroms, or below approximately30 Angstroms, or below approximately 20 Angstroms, or belowapproximately 10 Angstroms, or even below approximately 5 Angstroms. Thecontinuity referred to herein can be physical continuity or electricalcontinuity. In some embodiments of the disclosure the thickness at whicha material film may be physically continuous may not be the same as thethickness at which a film is electrically continuous, and vice versa.

In some embodiments of the disclosure, the rhenium-containing filmformed according to the embodiments of the disclosure, may have athickness from about 20 nanometers to about 100 nanometers, or about 20nanometers to about 60 nanometers. In some embodiments, arhenium-containing film deposited according to some of the embodimentsdescribed herein may have a thickness greater than about 20 nanometers,or greater than about 30 nanometers, or greater than about 40nanometers, or greater than about 50 nanometers, or greater than about60 nanometers, or greater than about 100 nanometers, or greater thanabout 250 nanometers, or greater than about 500 nanometers, or greater.In some embodiments a rhenium containing film deposited according tosome of the embodiments described herein may have a thickness of lessthan about 50 nanometers, or less than about 30 nanometers, or less thanabout 20 nanometers, or less than about 15 nanometers, or less thanabout 10 nanometers, or less than about 5 nanometers, or less than about3 nanometers, or even less than about 2 nanometers. In some embodiments,the rhenium-containing film may have a thickness between approximately0.1 nanometers and 50 nanometers, or between 1 nanometer and 30nanometers, or between 4 nanometers and 20 nanometers.

In some embodiments of the disclosure, the rhenium-containing films maybe formed on a substrate comprising high aspect ratio features, e.g., athree-dimensional, non-planar substrate. In some embodiments, the stepcoverage of the rhenium-containing film may be equal to or greater thanabout 50%, or greater than about 80%, or greater than about 90%, orgreater than about 95%, or greater than about 98%, or about 99% orgreater on structures having aspect ratios (height/width) of greaterthan 2, or greater than 5, or greater than 10, or greater than 25, orgreater than 50, or even greater than 100.

In some embodiments of the disclosure, the rhenium containing films maycomprise, pure rhenium, or rhenium and hydrogen, or rhenium, hydrogenand oxygen, or rhenium, hydrogen, carbon and oxygen, or rhenium, sulfurand oxygen. In some embodiments the rhenium containing films may furthercomprise impurities including, but not limited to, a halide (e.g.,chlorine, fluorine, iodine, or bromine), carbon, hydrogen, and nitrogen.

The rhenium-containing films formed according to the embodiments of thedisclosure may be utilized in a variety of technology applications. Asnon-limiting examples conductive rhenium oxide films may be utilized aselectrical interconnects, barrier layer films, as a portion of aSchottky diode device, as a portion of a metal-insulator-semiconductor(MIS) device, as a portion of a metal-insulator-metal (MIM) device, as aportion of gate electrode to a semiconductor device, such as NMOS orPMOS logic devices, or as an electrode to a semiconductor devicestructure, such as a DRAM device. In addition, certain rhenium oxidefilms, such as, for example, rhenium (VII) oxide (Re₂O₇), may exhibitdielectric properties and therefore may be utilized in DRAM devices, andin capacitor structures. Furthermore, rhenium sulfides, such as, forexample, rhenium disulfide (ReS₂), may behave in a manner similar to 2Dmaterials and may find applications in tribology, other low-fricationapplications, solar cell applications, quantum computing, and ultrafastdata processing.

As a non-limiting example embodiment, the rhenium-containing film maycomprise a conductive rhenium oxide film and may be utilized insemiconductor device structures including conductive interconnectionsfor electrically connecting one or more semiconductor device structures.

In more detail, FIG. 9 illustrates a semiconductor device structure 900which may comprise a substrate 902 which may include one or moresemiconductor device structures (not shown) formed into or onto asurface of the substrate. For example, the substrate 902 may comprisepartially fabricated and/or fabricated semiconductor device structuressuch as transistors and memory elements. The semiconductor devicestructure 900 may also comprise a dielectric material 904 formed overthe substrate 902, wherein the dielectric material may comprise alow-dielectric constant material, a silicon oxide, a silicon nitride, asilicon oxynitride, or mixtures thereof. The semiconductor devicestructure 900 may further comprise a barrier material 906, whichprevents, or substantially prevents, the diffusion of the conductiveinterconnect material 908 into the surrounding dielectric material 904.In some embodiments of the disclosure, the barrier material 906 maycomprise a rhenium-containing material formed according to theembodiments of the disclosure, such as, for example, a conductiverhenium oxide. The semiconductor device structure 900 may furthercomprise a conductive interconnect material 908 which may be utilized toelectrically connect semiconductor device structures formed in and/or onsubstrate 902. In some embodiments of the disclosure, the conductiveinterconnect material 908 may also comprise a rhenium-containing filmformed according to the embodiments of the disclosure. For example, theconductive interconnect material 908 may comprise a conductive rheniumoxide or an elemental rhenium formed by the methods disclosed herein.The semiconductor device structure 900 may also comprise a capping layer910, such as, for example, a conductive capping layer comprisingtitanium nitride (TiN), tantalum nitride (TaN), or tungsten (W).

Embodiments of the disclosure may also include a reaction systemconfigured for forming the rhenium-containing films of the presentdisclosure. In more detail, FIG. 10 schematically illustrates a reactionsystem 1000 including a reaction chamber 1002 that further includesmechanism for retaining a substrate (not shown) under predeterminedpressure, temperature, and ambient conditions, and for selectivelyexposing the substrate to various gases. A precursor reactant source1004 may be coupled by conduits or other appropriate means 1004A to thereaction chamber 1002, and may further couple to a manifold, valvecontrol system, mass flow control system, or mechanism to control agaseous precursor originating from the precursor reactant source 1004. Aprecursor (not shown) supplied by the precursor reactant source 1004,the reactant (not shown), may be liquid or solid under room temperatureand standard atmospheric pressure conditions. Such a precursor may bevaporized within a reactant source vacuum vessel, which may bemaintained at or above a vaporizing temperature within a precursorsource chamber. In such embodiments, the vaporized precursor may betransported with a carrier gas (e.g., an inactive or inert gas) and thenfed into the reaction chamber 1002 through conduit 1004A. In otherembodiments, the precursor may be a vapor under standard conditions. Insuch embodiments, the precursor does not need to be vaporized and maynot require a carrier gas. For example, in one embodiment the precursormay be stored in a gas cylinder.

The reaction system 1000 may also include additional precursor reactantsources, such as precursor reactant source 1006, which may also becoupled to the reaction chamber by conduits 1006A as described above.The reaction system may include additional precursor reactant source1008, which may also be coupled to the reaction chamber by conduits1008A, as described above. The reaction system may also include furtheradditional precursor reactant source 1009, which may also be couple tothe reaction chamber by conduits 1009A, as described. In someembodiments of the disclosure, precursor reactant source 1004 maycomprise a rhenium precursor, precursor reactant source 1006 maycomprise at least one of an oxygen containing precursor, a sulfurcontaining precursor, a boron containing precursor, or a hydrogencontaining precursor, precursor reactant source 1008 may comprise areducing agent precursor, and precursor reactant source 1009 maycomprise an oxidizing precursor. Therefore, in some embodiments of thedisclosure, the exemplary cyclical deposition processes 100, 200, 300,500, 600, 700, and 800 of the current disclosure may be performed in asingle reaction chamber.

A purge gas source 1010 may also be coupled to the reaction chamber 1002via conduits 1010A, and selectively supplies various inert or noblegases to the reaction chamber 1002 to assist with the removal ofprecursor gas or waste gases from the reaction chamber. The variousinert or noble gases that may be supplied may originate from a solid,liquid or stored gaseous form.

The reaction system 1000 of FIG. 10 may also comprise a system operationand control mechanism 1012 that provides electronic circuitry andmechanical components to selectively operate valves, manifolds, pumpsand other equipment included in the reaction system 1000. Such circuitryand components operate to introduce precursors, purge gases from therespective precursor sources 1004, 1006, 1008, 1009, and purge gassource 1010. The system operation and control mechanism 1012 alsocontrols timing of gas pulse sequences, temperature of the substrate andreaction chamber, and pressure of the reaction chamber and various otheroperations necessary to provide proper operation of the reaction system1000. The operation and control mechanism 1012 can include controlsoftware and electrically or pneumatically controlled valves to controlflow of precursors, reactants, and purge gases into and out of thereaction chamber 1002. The control system can include modules such as asoftware or hardware component, e.g., a FPGA or ASIC, which performscertain tasks. A module can advantageously be configured to reside onthe addressable storage medium of the control system and be configuredto execute one or more processes.

Those of skill in the relevant arts appreciate that other configurationsof the present reaction system are possible, including a differentnumber and kind of precursor reactant sources and purge gas sources.Further, such persons will also appreciate that there are manyarrangements of valves, conduits, precursor sources, purge gas sourcesthat may be used to accomplish the goal of selectively feeding gasesinto reaction chamber 1002. Further, as a schematic representation of areaction system, many components have been omitted for simplicity ofillustration, and such components may include, for example, variousvalves, manifolds, purifiers, heaters, containers, vents, and/orbypasses.

The example embodiments of the disclosure described above do not limitthe scope of the invention, since these embodiments are merely examplesof the embodiments of the invention, which is defined by the appendedclaims and their legal equivalents. Any equivalent embodiments areintended to be within the scope of this invention. Indeed, variousmodifications of the disclosure, in addition to those shown anddescribed herein, such as alternative useful combination of the elementsdescribed, may become apparent to those skilled in the art from thedescription. Such modifications and embodiments are also intended tofall within the scope of the appended claims.

What is claimed is:
 1. A method for forming a rhenium-containing film ona substrate by a cyclical deposition process, the method comprising:contacting the substrate with a first vapor phase reactant comprising arhenium precursor comprising an alkyl rhenium oxide precursor; andcontacting the substrate with a second vapor phase reactant comprising aboron containing precursor.
 2. The method of claim 1, wherein therhenium-containing film comprises at least one of a rhenium boride film,a rhenium sulfide film, or an elemental rhenium film.
 3. The method ofclaim 1, further comprising thermally annealing the rhenium-containingfilm after the cyclical deposition in a reductive environment.
 4. Themethod of claim 3, wherein thermally annealing the rhenium-containingfilm is performed at a temperature of greater than 350° C.
 5. The methodof claim 3, wherein thermally annealing the rhenium-containing film isperformed at a temperature of greater than 400° C.
 6. The method ofclaim 1, wherein the alkyl rhenium oxide precursor comprises methylrhenium trioxide (CH₃ReO₃).
 7. The method of claim 1, wherein thecyclical deposition process comprises an atomic layer deposition (ALD)process.
 8. The method of claim 1, wherein the cyclical depositionprocess comprises a cyclical chemical vapor deposition (CCVD) process.9. A semiconductor device structure comprising a rhenium-containing filmformed by the method of claim
 1. 10. A reaction system configured toperform the method of claim
 1. 11. A method for forming arhenium-containing film on a substrate by a cyclical deposition process,the method comprising: contacting the substrate with a first vapor phasereactant comprising a rhenium precursor comprising an alkyl rheniumoxide precursor; and contacting the substrate with a second vapor phasereactant comprising an oxygen containing precursor that comprises atleast one of sulfur trioxide (SO₃) and-formic acid (CH₂O₂).
 12. Themethod of claim 11, wherein the rhenium-containing film is a rheniumoxide film that comprises at least one of rhenium (IV) oxide (ReO₂),rhenium trioxide (ReO₃), rhenium (VII) oxide (Re₂O₇), or a rhenium oxidehaving the general formula Re_(a)O_(b), wherein a and b have a valueless than or equal to
 7. 13. The method of claim 12, wherein the rheniumoxide film comprises rhenium (VII) oxide (Re₂O₇) and the method furthercomprises contacting the rhenium (VII) oxide (Re₂O₇) with a reducingagent precursor thereby forming at least one of rhenium (IV) oxide(ReO₂), or rhenium trioxide (ReO₃).
 14. The method of claim 13, whereinthe reducing agent precursor comprises at least one of nitrogen monoxide(NO), a dione, sulfur dioxide (SO₂), an oxalyl anhydride, or an acid.15. The method of claim 12, wherein the rhenium oxide film comprises atleast one rhenium (IV) oxide (ReO₂), or rhenium trioxide (ReO₃) and themethod further comprises, contacting the rhenium oxide film with anadditional oxygen containing precursor thereby forming rhenium (VII)oxide (Re₂O₇).
 16. The method of claim 11, wherein therhenium-containing film comprises a rhenium oxide film and the methodfurther comprises, after forming the rhenium oxide film, contacting therhenium oxide film with an additional sulfur containing precursorthereby forming a rhenium disulfide (ReS₂) film.
 17. A method forforming a rhenium-containing film on a substrate by a cyclicaldeposition process, the method comprising: contacting the substrate witha first vapor phase reactant comprising a rhenium oxychloride; andcontacting the substrate with a second vapor phase reactant to form-arhenium boride film; wherein the rhenium oxychloride comprises at leastone of rhenium dioxytrichloride (ReO₂Cl₃), rhenium oxytetrachloride(ReOCl₄), rhenium oxypentachloride (ReOCl₅), rhenium di-oxy di-chloride(ReO₂Cl₂), rhenium oxydichloride (ReOCl₂), rhenium oxytrichloride(ReOCl₃), or rhenium oxychloride (ReOCl).
 18. A method for forming arhenium-containing film on a substrate by a cyclical deposition process,the method comprising: contacting the substrate with a first vapor phasereactant comprising at least one of a cyclopentadienyl rhenium hydride,or a cyclopentadienyl rhenium carbonyl; and contacting the substratewith a second vapor phase reactant to form a rhenium boride film. 19.The method of claim 18, further comprising thermally annealing therhenium-containing film after the cyclical deposition in a reductiveenvironment.
 20. The method of claim 19, wherein thermally annealing therhenium-containing film is performed at a temperature of greater than350° C.
 21. The method of claim 19, wherein thermally annealing therhenium-containing film is performed at a temperature of greater than400° C.